Sear and sear release for machine guns



' 1,530,702 H O. RUSSELL SEAR AND sEAR RELEASE FOR MACHINE GUNS Filed June 9, 1922 2 Sheets-Sheet 1 r1 7 9 l f' G) .i I

Patented Mar. 24, 1925.

HERBERT o. RUSSELL, or nos anenrns, oamronnm- SEAR AND SEAVRTR-ELEASE FOR MACHINE GUNS. f

Application file d' J'un'c 9, 1922. Serial No. 567,114.

T 0 all whom it may co /2 06am Be it known that I, I'IERBERT O; RUSSELL, a citizen of the United States, residing at Los' Angeles, in the county of Los Ange'les and State of California, have invented cer-.

tain new and useful Improvements in Sears and Sear Releases for ltlaehine Guns, of which the following is a specification.

This invention relates to a scar and sear release mechanism especially designed for anyof the mechanical po-sitivenes's of the firing mechanism of the gun.

The improved mechanism isintended to he used in connection with an electromagnetica-l trigger motor the direct action of which exerts the releasing pressure on the sear release. The action of the electric trigger motor is very fast and positive and the force exerted by it is comparatively small in order to reduce its size and weight. It is forthese reasons that the improved scar and sear release was designed in order that the action thereof might be very positiveand require but a small force to actuate.

In the Browning gun, a firing pin is retained in its retracted position by asear which has nsurface sliding on a surface of a pin, the two surfaces extending at ninety degrees from the. axis or line of movement of the. pin. considerable strength, the force required to slide the projection on the sear out of e11 gagement with the projection on the pin, is quite appreciable,aird the work done by the sear release slide, which is'op'erated upon by a trigger motor, in moving the sear, is too great for any except a. trigger motor of a' rather powerful type. It is therefore an objectof this invention to provide a firing pin and sear arrangement which may be released in a different manner so as to be operated without any great expenditure of force.

WVith the above and other objects in view, he invention consists in the novel construction, combination and arrangement herein fully described, illustrated and claimed. 1

In the accompanying drawings;

Since the firing pin spring is of Figure 1 is a fragmentary side elevation of the rear portion of the bolt of a machine gun, showing the present invention applied thereto.

Figure 2 is a rear end view of the bolt showing. the improved sear and sear release.

Figure is a perspective view looking at the rear end of the bolt.

Figure 4f is a similarview showing the sear and sear release displaced.

Fig. 5 is a vertical section through the rear end of the gun and bolt showing the cooperation of the various parts thereof, and

Fig. 6 is a detail View showing the engaged relation of the sear and firing pin.

'Referring to the drawings, 1 designates the belt of a machine gun which, as is well known, is mounted for reciprocatory movement and which carries the firing pin 2.

A firing pin spring 18 is provided which acts on the firing pin to force it to the left when released, see Figs. 1 and 5. The firingpin is provided on its upper side with a 1 pro ection 3 having a bevelled or cam face a to engage a depression forming a cam face ii: on a forward projection 5 on the sear 6.

The sear as shown in the drawings is mounted for verticalsliding movement in. a groove or guide way? in the rear end of the bolt 1 and is formed'with ribs 8 along the opposite. sidesthereof which work in channels 9 in the opposite side walls ofthegroove '7 thereby insuring accuracy of movement of the searand retaining the sear in working position. The sear is provided on the rear face thereof with a projecting lug 10 having which operates across the rear face of the sear. The cam face 12 is formed on a. projecting lip let of the sear release which lip 14 is adapted to engage over the lug 10 and hold down the sear 6 in engagement with the projection 3 on the firing pin thereby holding the firing pin in its retracted position. The cam faces 11 and-.12 cooperate to re-set the sear and sear release in the recoil of the bolt. It will be understood that the firing pin travels only a short distance forward after it is released, this distance being sufficiently small so that the lower part of the sear is always touching some part of the upper portion of the firing pin. The spring 17 always presses downwardly upon the sear. After the gun is fired, the sear is cammed upwardly by the firing pin and the a cam face 11 designed to cooperate with the cam face 12 of a slidable sear release 13 recoil of the gun'operates upon the firing pin .in the customary manner so that it is moved in relation to the bolt to again assume the position shown in Fig. 1 and so as to permit the spring 17 .to force the sear down upon the cam faces'of the firing pin as shown in Figs. 1 and 5. When the sear is moved downwardly by the spring 17 the cam faves 11 and 12 cause the slidable sear release 13 to move to the right from the position shown in Fig. Qand as soon as the sear has reached its position was to engage the firing pin as shown in Fig.1, the spring 16 ofthe sear release operates to move the sear release to theleft so that-it locks the sear in its down or cooked position. 7

At one end the sear release 13 has a forwardly projecting extension or spring seat 15 against which bears the outer end of a sear release springlG, the inner end of which is seated against the base ofa recess formed in the bolt to receive said spring. A:leaf spring 17 has its free end in engagement with the top of the sear 6 so as to force the sear downwardly into engagement with the firing pin 2, at the same time causing the sear release 13 to bemoved horizontally in order that the projection 10 may get under the lip 14 of the sear release.

disengaged from it.

- Having thus described'my invention, I claim: g

1. In a machine gun, the COIIlbllltLtlOl'r The operation of the mechanism is as follows. Considering the gun. to be cooked,

with the sear, sear release and firing pin all engaged. The engagementof'these parts is retained through the direct action of the firing pin and sear release and coil springrespectively, When the electrictrigger. motor is energized, the plunger of said motor strikes the end 15 of the sear release, forcing therlatter inwardly until the sear becomes The scar is then cammed by means of the force produced by the firing pin spring, the firing pin going forward immediately. The recoil of the gun automatically brings all of the aforenamed parts back to their original or cooked position to await the next impulse of the plunger on'the sea-r release.

withthe gun bolt, of a sear having a cam faced lug thereon, and a sear release movable across the path of the lug of the sear and having a cam-faced lip to engage and hold positively holding said sear and pin engage 3. In a machine gun, the combination" said sear for bodily slidlng movement t erem, and re-' 'leasable means for with a gun bolt,- of a firing; pin, a sear,

bodily movable in a direction at right angles to the path of movement of said pin, said sear having a cam face to. engage said pin,

guides in theg'un bolt for mounting said sear so as the sear can be cammed by said'pin and releasable means for positively holding'said sear and pin engaged. V

4. In a machine gun, the combination with the gun bolt, of a firing pin, a cam face on said pin, a scar, a guide in said gun bolt for mounting said sear for bodily sliding movement at right, angles to the, movement of the firing pin, so as the sear may be cammed bythe cam face of the firin pin, a sear release for normally positively Iocking. said sear and pin in engagement, and a spring for holding said sear release in engagement with said sear. r I

5. In amachine gun, the combination with the gun bolt, of a firing pin, a cam. face on said pin, a sear, afguide for mounting said sear so. as the sear may be cammed by the,

cam face of the firing pin, a sear release for normally positively locking said sear and pin in engagement, and a spring for holdin said sear release in engagement'with said sear, said sear and sear release being movable along paths ninety degreesapart.

6. In a machine gun, the combination with the gun bolt, of a firing pin, a cam face on said pin, a sear, a guide for mounting said searso as the sear may be cammed by the cam face of the firing p.in,'a. sear release for normally positively lockingsaid sear and pin in'engagement, and a springfor holding said sea-r release in engagement withsaid sear, said sear, ,sear release andfiring pin all being movablejalong paths ninety? degrees apart in said gun bolt. i

In testimony whereofI afiix my signature.

HERBERT O. RUSSELL. 

